I have done a complete swap on a DeLorean I owned and can give you a bit of advice. Make sure you buy "warm white" LEDs and not just white. White LEDs are more of a blue/white where warm white gives off something much more soothing to the eyes. Its looks much more natural. The DeLorean was unique in that all the lights power went through the light switch...which in turn usually heated up said switch. Eventually, the switch wears out from from this. Adding LEDs made an amazing difference in the legibility as well as the draw on the battery. Also, given that is customary to leave the doors open a car show or when people wanted to have a look, I changed out the lights that were on the leading edges of the doors. Its was great to know that I was not draining the battery too much with the doors open anymore.
One thing I found annoying though was that I replaced the headlight indicator lights with LEDs. For whatever reason, the DeLorean had indicators for both dip and high beams. One or the other were always on with the lights. The LEDs were so bright that I found them VERY distracting. I ended up replacing them with standard bulbs but kept the LEDs in the rest of the binnacle. They REALLY brightened things up.
On the subject for lightning upgrades, I have another recommendation for the Mini. Maybe its because I dont drive me every day but I cant stand the lack of light inside the car at night. Not a fan of feeling around for the center switches. I bought a kit from a guy here in the US that made all the switches light up dimly when the ignition is switched on. I also replaced the unlit headlight switch (on SPi car) with a lit one. I made my own first but then found out they actually made a lit switch. Maybe it was for a Rover but its great. When I switch on my ign, I know can see all the switches as well as while driving. The kit even allows me to adjust the brightness of them.